Boychuk went feet-first into the end wall in the third period against the Carolina Hurricanes on Saturday. He returned to the game but wasn't able to take part in the morning skate with the Bruins on Monday.
"He didn't skate this morning because he can't," Bruins coach Claude Julien said. "Right now he's too sore, so he's day-to-day. It's from obviously the incident [Saturday], and so he couldn't skate this morning. He came in early and we tried to see if he could and he couldn't."
Boychuk has three goals, 20 points and a plus-30 rating in 63 games.
Julien said the Bruins will dress seven defensemen for the pregame warm-up and decide who's scratched at game time. The top candidate to play would be Andrej Meszaros, who was scratched against the Hurricanes.
"Obviously we're playing a team that's very deep, a team that's going to play four lines and play them effectively," Wild coach Mike Yeo said. "So we're looking to see [Fontaine] come in and hopefully get right to where he was when he came out of the lineup. Obviously when we added a couple players it had a big impact on a lot of guys, and probably him more so than anybody. But when he's playing well he's playing a strong game in the offensive zone, he's executing along the wall and he's a reliable two-way player."
Fontaine has 12 goals and six assists in 54 games this season.
Here are the projected lineups for both teams: